<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="app">
    <h2>{{message}}</h2>
    <!-- 1.单选-->
    <select name="kai" v-model="selected">
        <option disabled value="">请选择</option>
        <option value="a">A</option>
        <option value="b">B</option>
        <option value="c">C</option>
    </select>
    <br>
    <span>Selected: {{ selected }}</span>

    <!-- 2.多选-->
    <br>
    <select name="kai" v-model="selecteds" multiple>
        <option disabled value="">请选择</option>
        <option value="a">A</option>
        <option value="b">B</option>
        <option value="c">C</option>
    </select>
    <br>
    <span>Selecteds: {{ selecteds }}</span>
</div>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
<script>
    const app = new Vue({
        el: '#app',
        data: {
            message: 'simplelu',
            selected: 'c',
            selecteds: [],
        }
    })
</script>
</body>
</html>